Threaded openings are used in countless applications to thread one component into another. As one example, the heads on engines typically have a plurality of threaded openings in the parent material of the head that threadably receives a sparkplug therein. In this arrangement, the sparkplug is quickly and easily installed and removed by threading the sparkplug into or out of the threaded opening in the head. While this arrangement is convenient, effective and generally durable, a substantial problem is presented in the event that the threads in the parent material become worn or damaged.
There are several methods available to attempt to repair or rehabilitate worn or damaged threads. One such arrangement is known as tapping. Tapping is achieved by inserting a special insert into the threaded opening which attempts to re-align, or rehabilitate the existing threads. While tapping may be effective in some applications, tapping is generally limited to applications where only minor damage has occurred to existing threads. Generally speaking, tapping is ineffective if the existing threads are substantially worn or stripped. Tapping is certainly not effective when there is not enough material left to re-form the threads. Also, generally speaking, tapping is ineffective if there is substantial damage to the threads, like missing chunks, or substantial deformation. In addition, many forms of metal are not particularly well suited for or receptive to tapping. As such, substantial deficiencies exist in this method of repair.
Another method of repair includes the use of coil or mild steel inserts to replace the worn or damaged threads in the parent material. One example is that manufactured under the name HELICOIL® by Stanley Engineered Fastening, 480 Myrtle Street, New Britain, Conn. 06053. Another example is that manufactured under the name TAP-LOK™ by Groov-Pin Corporation, 1125 Hendricks Causeway, Ridgefield, N.J. For some applications repairs utilizing this method requires field boring the damaged threads, welding in an insert followed by field boring again followed by tapping the newly bored opening. While this method of repair is effective in some applications, this method suffers from many substantial disadvantages. Namely, replacement of the damaged threads in this manner is a labor and time intensive repair that requires a skilled craftsman equipped with highly specialized tooling. In addition, due to the material properties of these inserts, the repaired threaded opening tends to be weaker and less durable than the original threads. This often leads to premature failure of the repaired threads. As such, substantial deficiencies exist in this method of repair.
Several attempts have been made at developing thread repair inserts that resolve these and other deficiencies. One such example is presented in U.S. Patent Publication No. 2004/0136807 entitled “Thread Repair Insert” to Thomas F. Foerster Jr. which presents a thread repair insert having at least one containment recess therein. Other examples include U.S. Pat. No. 8,052,360 entitled “Self-Aligning Thread Tap and Method of Utilizing the Same to Tap Existing Bore Holes”; U.S. Pat. No. 7,819,613 entitled “Self-Tapping Insert and Method of Utilizing the Same to Replace Damaged Bores and Threads” and U.S. Pat. No. 8,439,617 entitled “Self-Tapping and Self-Aligning Insert to Replace Damaged Threads” all to Carl Strom. While these references teach methods or means of repairing damaged threads they all provide sub-optimal resolutions as the repairs themselves are weaker than the original threaded opening and therefore are susceptible to premature failure.
Therefore, for the reasons stated above, and for other reasons stated below which will become apparent to those skilled in the art upon reading and understanding the specification, drawings and claims there is a need in the art for an improved thread repair insert. Thus, an object of the invention is to provide a thread repair insert that improves upon the present state of the art.
Another object of the invention is to provide a thread repair insert that provides a rugged repair.
Yet another object of the invention is to provide a thread repair insert that provides a durable repair.
Another object of the invention is to provide a thread repair insert that that has a long useful life.
Yet another object of the invention is to provide a thread repair insert that is easy to install.
Another object of the invention is to provide a thread repair insert that is repeatable.
Yet another object of the invention is to provide a thread repair insert that can be installed without highly specialized tooling.
Another object of the invention is to provide a thread repair insert that can be easily installed.
Yet another object of the invention is to provide a thread repair insert that can be quickly installed.
Another object of the invention is to provide a thread repair insert that does not require a skilled machinist to install.
Yet another object of the invention is to provide a thread repair insert that provides exceptional tear out strength.
Another object of the invention is to provide a thread repair insert that provides exceptional pull out resistance.
Yet another object of the invention is to provide a thread repair insert that does not require a custom manufactured solution for each repair.
Another object of the invention is to provide a thread repair insert that eliminates the need for welding.
Yet another object of the invention is to provide a thread repair insert that can be used in countless applications.
Another object of the invention is to provide a thread repair insert that can be used with any kind of thread design or style.
Yet another object of the invention is to provide a thread repair insert that is safe to use.
Another object of the invention is to provide a thread repair insert that is safe to install.
Yet another object of the invention is to provide a thread repair insert that provides a cost effective repair.
Another object of the invention is to provide a thread repair insert that is efficient to use.
Yet another object of the invention is to provide a thread repair insert that eliminates the need to replace larger parts or components.
Another object of the invention is to provide a thread repair insert that provides optimal wear resistance.
Yet another object of the invention is to provide a thread repair insert that provides a permanent repair.
These and other objects, features, or advantages of the invention will become apparent from the specification and claims.